The present invention relates to a method and apparatus for removing biofilm, bacteria, fungal cells, spores, fragments, and hyphae, microbiological slime, and organic contaminants from porous and non-porous surfaces, maintaining the integrity and life expectancy of the substrates, and increasing their resistance to formation of new biofilm and microbiological deposits. The present invention further relates to a method and device that includes modification of cellulosic and non-cellulosic materials to increase the negative electrostatic potential of their surfaces to resist microbial and organic contaminant attachment and growth into biofilms and deposits. It also relates to a method to safely and economically create, control, and apply a blend of a peroxide composition and an alkaline composition in specialized equipment as a highly aggressive antimicrobial and organic contaminant destroyer in a super-activated solution known by those skilled in the art to normally cause extreme hazards including volatility, pressure and temperature buildup, and explosiveness, as well as to lead to wasteful use of the compositions and blends due to rapid breakdown of the peroxide composition, its super-activated blends, and its more active byproducts. It further relates to a method to maintain the highest demulsifying and antimicrobial activity of an organic acid composition blended with a peroxide composition by dual feed of the separate compositions through specialized equipment designed to limit contact time and level of degradation of the optimum components of the organic acid composition.
Damage from floods and storms such as hurricanes or tornadoes, beyond causing catastrophic destruction of buildings and structures, leaves behind heavy contamination including mud, dirt, debris, and microorganisms such as mold and yeast (fungi), and bacteria. Additionally, water damage caused by leaking and broken pipes and condensation can create environments where contamination by similar microorganisms can allow them to reproduce, thrive, and cause problems. Remediation and restoration of contaminated buildings and structures often involve substantial manual removal efforts such as wiping, scraping, and mopping, but both organic materials and microorganisms normally invade hard-to-reach areas including cracks and crevices in surfaces such as wood, under carpet pile, beneath flooring and tiles, and behind wall coverings. The residual contamination remaining behind after even careful manual cleaning can lead to ongoing structural degradation such as wood rot, air contamination that can cause severe health issues such as from allergies, and horrible odors that make working or living in contaminated structures very difficult or even impossible.
Fungi (yeast and mold) are recognized by medical and veterinary experts as causing a very broad spectrum of health issues in both people and animals. Severe allergies lead to year-round challenges including nasal stuffiness, coughing, eye irritation, skin irritation, breathing problems, accelerated or irregular heartbeats, asthma, and even pneumonitis. More severe problems can occur with infections such as kidney and liver failure, and worsening of other disease conditions such as with cystic fibrosis. Mycotoxins produced by fungi can cause illnesses, weakened immune systems, poisonings, and even death; even though relatively rare, Stachybotrys has been recognized for its threat as the “toxic black mold”. Even “sick building syndrome” is now being identified as probably associated with residual mold contamination.
Bacteria can also contaminate buildings and structures after storm, flood, and water damage. Even though requiring a higher level of water for survival, degradative and pathogenic bacteria can find harbors of sufficient moisture in microenvironments where they can continue to survive, especially where substrates maintain residual moisture, organic contaminants have built up, or in areas where dehumidification efforts are less efficient. Diseases such as leptospirosis, cholera, typhoid, and hepatitis, especially where gray water from household contamination or black waters from sewage and sanitation occur, can be initiated by contact with damp surfaces or by inhalation of moisture or bacterial spores during the drying process.
In addition to causing disease and health issues, remaining colonies of fungi and bacteria can cause structural damage including rotting of cellulosic materials and corrosion of metals and other materials of construction. Wood rot organisms utilize cellulose as a foundation, source of moisture, and location for organic food sources. Insufficient or inconsistent dehumidification allows degradation of the structural integrity of wood and wood-containing materials, as well as maintaining environments where pests such as termites can feed and thrive.
Remaining biofilm and biodeposits can lead to corrosive destruction of surfaces including metals such as carbon steel, stainless steel, aluminum, copper, and brass, and non-metals including concrete, polymers and polymer composites, and plastics. Aerobic bacteria within biofilms and deposits establish differential aeration cells that lead to pitting corrosion damage and premature failures. Additionally, anaerobic bacteria such as sulfate-reducers can greatly increase the speed of microbiological pitting where they find protective havens underneath microbiological and organic deposits. Even materials normally resistant to microbiological corrosion and degradation can be damaged by microorganisms thriving on adjacent materials such as wood that are better recognized for their supporting environment. Residual organic fouling and microbiological growth can lead to structural damage and health issues many years after the initial contamination.
Current cleanup efforts focus on diminishing moisture content, which does help reduce the extent of bacterial and fungal threat and damage. However, there is more than enough residual moisture and condensation to support microbiological growth. Fungi (yeasts and molds) can survive on the exterior surfaces and roofs of buildings and structures with only the limited moisture from the environment and the building materials themselves. Where contamination has already occurred such as during floods and storms, residual moisture from just high humidity and elevated temperatures can leave wood components susceptible to rotting organisms. Micro-colonies can also survive until sufficient condensation occurs to reactivate the organisms and lead to thriving communities that threaten the people that inhabit and work in these buildings, their pets, and even the structures themselves.
To reduce or prevent concerns, simple surface cleaning and disinfection must be enhanced by improved attack, destruction, and removal of the microbiological and organic contaminants.
Existing treatments include application of both oxidizing and non-oxidizing biocides. With the concerns of potential human and pet exposure, much of the post-contamination efforts focus on use of oxidizing compounds such as chlorine and/or bromine and non-chlorine peroxide compounds. Chlorine and its other related compounds including hypochlorite and chlorine dioxide have application concerns due to direct chemical attack of materials, along with newer issues over creation of hazardous and potentially carcinogenic byproducts. Therefore, as byproducts of peroxide compounds are simply non-toxic oxygen and water and do not threaten creation of hazardous byproducts and are less prone to structural degradation, they have grown in usage for cleanup and remediation efforts.
Peroxide compounds including hydrogen peroxide, percarboxylic acid, perboric acid, persulfuric acid, metal salts of these compounds, and other peroxide and peroxide-releasing compounds have been used with moderate success. Their ability to penetrate and remove contamination is enhanced by inclusion of surfactants, while the products' resistance to decomposition has been improved by use of stabilizers. However, the antimicrobial efficacy and chemical reactivity of the peroxide compounds is still often insufficient to address all the contamination They rapidly degrade to their inactive byproducts especially in the presence of heavy organic fouling and metals and metal ions including iron, manganese, copper, silver, platinum, and titanium, and they are rapidly broken down to inactive molecules by enzymes including catalase, peroxidase, and other less common ones normally present in all of the targeted microorganisms. The anti-peroxide reaction rate for catalase has been reported as high as 5,000,000 molecules destroyed per enzyme molecule per second, making sufficient treatment by, for example, 8% hydrogen peroxide, almost impossible to achieve; in the presence of substantial microbial populations and/or substantial organic contaminant presence, the hydrogen peroxide is inactivated faster than it can reach the targeted surfaces. Even with very little organic fouling present, peroxide compounds, without the super-activation of the current invention, at or below 8% concentration, are typically broken down to inactive compounds faster than they can accomplish their targeted tasks of killing microorganisms, destroying organic contaminants, and lightening stains.
Hydrogen peroxide is well-recognized for its use to kill bacteria, fungi, viruses, and other microorganisms, and it also is inherently a vital part of all cell metabolism including destruction of internal cell toxins. With external application targeting microorganisms, it offers an extremely broad spectrum of effect including attack of critical cell components such as lipids, proteins, DNA, sulfhydryl groups, and organic compound unsaturation. However, as the cells both produce and are attacked by hydrogen peroxide, there are natural processes that operate to limit the lifetime of and turn off the destructive capability of excess hydrogen peroxide. The primary defense for cells to limit the danger of hydrogen peroxide is through enzymes including catalases and peroxidases. Lower concentration and limited contact by peroxide serve to activate these defense mechanisms, and, therefore, hydrogen peroxide has been historically much less beneficial an antimicrobial than desired.
Acids are known to alter the physical structure of enzymes such as catalase to inactivate their anti-peroxide activity, but recognition by the cells of increased peroxide presence leads to an expanded response by them. The acid-inactivation of enzymes is a reversible reaction, and the increase in, for example, catalase concentration can rapidly turn a seemingly effective peroxide treatment level into an insufficient residual. Some organic acids are able to stabilize the enzyme deformation and prolong the peroxide residual presence, but this improvement still has a limited life.
Additionally, some bacteria respond to chemical threats including peroxide attack by formation of protective spores. Even though this does not create bacterial strains specifically resistant to hydrogen peroxide, it makes killing the organisms much more challenging. Even with extremely high concentrations of peroxide, an antimicrobial treatment by hydrogen peroxide on its own can prove ineffective.
To better address the level of contamination and the need for a higher activity of cleaning and remediation products, alkaline materials have sometimes been used to enhance the peroxide compositions through development of free radicals. In alkaline conditions, hydrogen peroxide initially forms perhydroxyl anions (HOO−), also referred to as hydroperoxide anions, which are strong nucleophiles. Perhydroxyl anions, though, are not very stable in aqueous solutions, and they rapidly convert to a wide variety of very reactive free radicals including perhydroxyl (HOO.), hydroxyl (.OH), superoxide anion (.O2−), and oxyl anion (.O−). The enhanced activity of these alkaline initiated radicals against microbial and organic contaminants, in spite of the rapid rate of peroxide activation, has been of limited practical value, as these structures rapidly break down to non-reactive species and have extremely short life, leading to poor efficiency, product over-application, and substantial waste as the degraded compounds become ineffective.
Levels of degradation of the base peroxide compositions, their alkaline-activated blends, and their reactive species including free radicals, change severely with variables including concentrations of metal and organic contaminants in the compositions, time, pressure, temperature, and pH. Therefore, actual field applications of peroxide compounds at elevated pH's have historically been inefficient, inconsistent, and undependable. To provide beneficial effect with these type chemistries, applications must offer consistent, dependable, economical, and thorough coverage. This beneficial effect can not be achieved with historic application equipment, as ratios of the blends were not maintained as optimized, the rate of degradation was excessive, and degradation rates did not leave sufficient activity to produce the targeted results. New application equipment design is a prerequisite to producing much more predictable and consistent composition blends that would not allow overly sufficient contact during which such degradation could occur.
Application of technologies based on peroxide and alkali combination through a dual and simultaneous feed has not been commercially viable. The mixture of the peroxide and alkaline compositions creates an extremely violent, exothermic and explosive reactions with release of substantial heat and flammable oxygen that literally threatens the lives of application personnel. Heat and pressure buildup are known to cause runaway degradation and explosive reactions, especially when triggered by even minimal contamination from metals or organic compounds, that can damage feed lines, chemical containers, and mixing systems, as well as lead to injuries and chemical exposure. Attempts to use lower concentration peroxide compounds such as less than 8% hydrogen peroxide can slightly reduce the threat, but they are not sufficiently active to accomplish the targeted application needs on their own.
In some historic efforts, the organic contaminant removal and antimicrobial efficacy of a peroxide composition has been enhanced by blending into the formulation at least one organic acid. Some medium length (C5-C12), straight chain, fully saturated, carboxylic acids add their own antimicrobial activity to that of the peroxide composition through disruption of microbial cell wall components. Additionally, the activity of these organic acids as surface active agents helps improve penetration and disruption of surface fouling by organic compounds. Further, these acid compounds help distort the physical structure of enzymes including catalase that destroy peroxide compounds such as hydrogen peroxide at unbelievably rapid rates, at least temporarily inactivating the enzymes and allowing much of the peroxide compositions to survive and achieve their targeted benefits in removal and destruction of microbial and organic contaminants
However, peroxide compositions, especially in acid environments below about pH 6 where the acid serves to activate the peroxide components to stronger oxidizers, will destroy both the targeted organic and microbial contaminants as well as the organic acids, themselves. Each oxidation by these activated compounds of the organic acids causes them to lose a carbon dioxide molecule during every reaction, creating new organic carboxylic acids that are one carbon length shorter than the originals.
Various chain length organic acids have been extensively evaluated for their antimicrobial efficacy and their surfactant capabilities, and optimum treatment in cleaning and disinfection was targeted by selection of specific organic acids. In spite of this, though, oxidative degradation by peroxide compositions of the chosen organic acids worsened by factors including increasing time, temperature, and pressure, results in a less than optimum group of organic acids that creates inefficient applications, requirements for wasteful overfeed, and inconsistent treatment that leaves voids and openings for rapid failure of restoration and remediation.
As an example, caprylic acid (C8) offers better demulsification and higher antimicrobial efficacy than heptanoic acid (C7) and would optionally be chosen over heptanoic acid to activate and improve the application of a peroxide composition. Improved demulsification from selection of an organic acid such as caprylic can help break emulsified organic materials at the targeted surfaces such as metals to enhance their removal, but it is of even more value when water is being recycled or recirculated for reuse; with allowance of some time for separation, inclusion of an effective demulsifier allows the mechanically entrapped organic compounds to phase separate from the water for easier removal by methods including skimming. Further, demulsifiers allow effective surfactant activity with lower foaming tendency, allowing for lower foam applications where they are desirable, such as with use under high pressure. Additionally, especially where mold remediation is the target of an application, the enhanced antifungal activity of caprylic acid over heptanoic acid would produce more effective results. However, oxidative degradation of the organic acid by the peroxide compounds rapidly changes the original organic acid components from their original chemistry and concentrations. Even with only a limited extension of contact time between the peroxide composition and the organic acid composition in standard pump-up sprayers or pressure washers, a large percentage of the caprylic acid would be oxidized to the much less effective heptanoic acid. Also, in single product formulations with both peroxide component and organic acid components, extended warehouse storage product could, even though the effects might not be visibly or physically observable, greatly reduce the cleaning and antimicrobial efficacy as compared with more recently manufactured material.
To avoid this potential oxidative degradation that would negatively impact the efforts to remove and destroy organic and microbiogical contamination, it might seem obvious to simply and separately apply a peroxide composition and an organic acid composition to the site of the targeted application. However, optimized and tight control over the ratio between the two compositions, efficient dosing and mixing of each composition, and the amount of contact time prior to application must be maintained to achieve the most efficient, economical, consistent, thorough, and dependable treatment applications. New application equipment designed for a dual and simultaneous composition feed is needed to produce much more predictable and consistent composition blends without leaving excessive contact time or other conditions during which organic acid degradation and resultant inefficiencies could occur.
The specialized application apparatus of the present invention allows for the safe and cost-effective use a dual chemical feed of a peroxide composition and an alkaline composition or a peroxide composition and an organic acid composition to create an enhanced activity blend used to treat targeted surfaces for removal and destruction of microbiological and organic contamination of both porous and non-porous surfaces. Almost immediately after the blending of the two compositions, the mixture is rapidly applied to those surfaces to ensure that the optimum and intended combination is achieved and distributed.